Expandable bands are commonly used to secure flexible sealing elements or gaskets against an internal surface of a pipe, manhole, or other similar structure. Expandable bands typically fit against an annular surface within the sealing element and are expanded to apply pressure against the sealing element. Various types of locking mechanisms are used to lock the band into the expanded position against the sealing element.
The existing bands and locking mechanisms, however, have a number of limitations and disadvantages. Many of the existing expandable bands are expandable to only one diameter and therefore have a limited overall expansion range. Many of these bands also require a number of steps to both expand and lock the band and are not capable of quickly and securely locking the band over a range of diameters. Moreover, the existing expandable bands are difficult to release or "unlock" and cannot easily be removed or adjusted to a smaller diameter. Other existing bands do not slide easily or bind being installed or adjusted. Overall, the existing bands are not useful with seals of various sizes that need to be installed in pipes or manholes having various sizes.
Accordingly, a need exists for an expandable band that is easily installed, adjusted and securely locks over a range of diameters. A need also exists for an expandable band that is more easily released from a locking position.